Brake



Ma 2s, 1929. E, P, REQAUX j 1,715,211

BRAKE Filed April 15, 19215 I 1 mvEN'rpR 4 EU GEQE RRENAUX ATTORNEY Patented May 28,1929;

um- E STATES PATENT OFFICE;

EUGENE PROSPER RENAUX, OF PARIS, FRANCE, ASSIGN OR TO BENDIX BRAKE COM- PANY, .OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS.

BRAKE.

Application filed. April 15, 1926, Serial This invention relates to brakes and is illustrated as embodied in an internal expand ing brake for an automobile wheel operated bya servo device engaging the outside of the brake drum. v 1

, An object of the invention is to provide siniple connections through which the servo shoe applies the brake and also by meansofwhich the servo shoe itself is forced against the brake drum. In one desirable arrangement friction means engageable with the inside of the brake drum, such as a pairof substantially rigid shoes anchored at the bottom of the drum, is arranged to be expanded against the 15 drum by a device operated by an arm extending outside of the brake drum and engaged by the servoshoe, this bringing the servo shoe to the top of the brake drum where-it is in a comparatively protected position, p i

' Another feature relates to operating the servo shoe to force it against the outside of the drum by means of interconnected spaced' devices such as cams which permit it to have a substantial angular movement with the drum.

The above and other objects and features of the invention, including various novel combinations of parts and desirable particular constructions, will be apparent from the following description of one illustrative embodiment shown in the accompanying drawing, in which: i

The figure is a vertical section through the brake just between the open side of the drum 3 and the-usual backing plate and showing the brake shoes in side elevation.

The particular brake selected for illustration includes a rotatable brake drum having the usual peripheral cylindrical brakin flange, and which in practice is usually close at its open side by a backing plate or the like which not shown. Within the drum is arranged the friction' means of the brake i1- lustrated as a pair of semi-circular andsubstantially rigid brake shoes 12 and '14 anchored at the bottom of the drum'by being mounted on pivots 16 and 18 projecting from Y the backing plate towards the head of the At the upper-ends the shoes may be connect ed by a tension spring 20 serving as a return spring resisting the movement of the shoes against the drum' by the brake-expan g means which may be an expanding device $110 as a double cam 22 mounted on a spindle 24 No. 102,134, and in'France June a, 1922.

carried by the backing plate and turned 'by a lever- 26 aving a part projecting outside the circumference of the 'brake drum. For convenience of illustration, shoes 12 and 14 are shown in their on positien,that is, in engagement with the inner surface of the drum, whereas the cam 22 is shown in its off, position', in which it is substantially vertical.

The brake is a plied bya servo shoe or the like 28 engageab e with the outer surface of the brake drum and shown as asubstantially rigid arcuat-e floating shoe. This, shoe is notched out as shown toembrace the bend end of the lever 26 so that when the servo shoe moves angularly with the drum it will rock the cam 22 to force shoes 12 and liapart against the drum. The servo shoe 28 is forced against the drum in, applying the brake, against the resistance of a pair of return springs 30 and 32 connected at its ends, by inter-connected spaced applying devices shown as'a pair of cams 34 and 36. These cams have arms 38 shown formed with intermeshing gear or rack teeth so that when the cam 36 is operated the cam 34 is simultaneously operated. The cams 34 and 36 may be mounted onspindles carried by an extension of the backing plate of'the brake. The cam 36 is provided with an operating arm' or lever 40 which operates both of the camsto apply the brake. When the brake is released, the. springs 30 and 32 pull the servo shoe 28 away I from the drum as far as permitted by the cams 34 and 38, while the spring 20 serves the double purposeof releasing the shoes 12 and 0 14 and of acting through the cam 22 and the arm 26 to return the servo shoe 28 to a central initial position.

While one illustrative embodiment has been described in detail, it is not my intention to I limit its scope to that particular embodi- 'ment or otherwise'than by the terms of the appended claims. Most of the -subject-matter herein claimed is tobe regarded as continued from my application No. 625,07 2, filed March I claim: 1. A brake comprising, in combination, a rotatable drum, friction means engageable,

gaging the end of said part, means for forc 10 with the inside of-the drum, an operating de- '105 vice for expanding the friction means against the drum incli ding a part extending outside ing the servo shoe against theoutside of the drum, and springs on oppositesides of said means urging the servo shoe away from the drum.. 4

2; A brake comprising, in combination, a rotatable drum, friction means engageable with the inside of the drum, an operati ng de vice for expanding the friction means against the drum including a part extending outside of the drum, av substantially rigidservo shoe engageable with the outer surface of the drum and notched to embrace the end of said part,

and inter-connected spaced devices acting on spaced parts of the rigid shoe for forcing the servo shoe against the outside of the drum.

' 3. A brake comprising, in combination, a

' rotatable drum, friction means engageable with the inside of the drum, an operating device for, expanding the-friction means against the drum including a partextending outside of the dra n, a servo shoe engageable with the r outer surface of the drum and notched to embrace the end of said part, and inter-connected spaced cams for forcing the servo shoe against the outside of the drum;

4. A brake-comprising, in combination, a

' rotatable. drum, friction means. engageable .withone side of the drum, a substantially rigidrelatively short servo shoe engageable with theother side of the drum and arranged to force the friction means against the drum, and inter-connected spaced devices engaging spaced the servo shoe against the drum. i

.5. A-brake comprising, in combination, a.

rotatable drum; friction means engageable portions of said rigid 51 f lfin g 7 with one side of the druii agservo shoe en'- gageablewith the other side'of'the drum and arranged to force the friction means against the drum,-- and inter-conneotedspaced 'cams for-forcing the servo shoe against the drum.

6. Brake mechanism comprising, in comhination, a brake drum, internalbrake shoes supported within the drum to be moved thereagainst, a short'infiexiblo servo shoe outside the drum to be-inoved thereaga nst by cam means and to be rotatably actuated by said drum, operating mechanism connecting the servo shoe with the internal brakeshoes to act-uate them upon rotatable movement of the servo shoe. i

7. A brake compris ng, iii combination, a

rotatable drum, friction means engageable with one side of 'th edruin, a'fsub'stantially rigid servo shoe. cngageable with the other side of the drum and arranged to. force the friction means against the drum, and inter- EUGENE PRO SPER B-ENALUX. 

